Robot assemblies are an important component in automation, especially in manufacturing facilities and manufacturing equipments. For example, in the semiconductor industry, robot arms are used to handle semiconductor wafers, flat panel display, LCD, reticles, masks, or carrier boxes.
In the semiconductor fabrication facility, robot can be used to transport work pieces, typically stored in carrier boxes, from one location to another location, from one equipment type to another piece of equipment. In a process system, a robot is typically used to remove the work pieces from the carrier boxes, and then load them into a load lock. Another robot can be used to move the work piece from the load lock into a processing chamber and from one processing chamber to another processing chamber. Thus within a processing system, there might be a plurality of robots, each one is designed for a particular task. The processing system could be a deposition system, an etch system, a lithography system, a metrology system, an inspection system, an implantation system, a treatment system, or any work piece processing system.
Another type of equipment is supplemental equipment such as a stocker, designed for storing the work pieces until needed, or a sorter, designed for sorting the work pieces into certain desirable order. In a typical bare stocker system, a robot is typically used to remove the work pieces from the carrier boxes, and then load these pieces into a load lock. Another robot can be used to move the work piece from the load lock into a storage chamber, where the work pieces are stored without the original carrier boxes. For a box stocker system, the work pieces are stored together with the carrier boxes, without the need for removing them out of the carrier boxes.
Robot handling can be considered overhead operation, since the purpose of robot handling is to transport the work pieces between locations. Thus to improve the efficiency of the fabrication facility and to improve the throughput of the equipment, faster movement of robots, and multiple robot assemblies can be used. Thus some equipment provides a robot assembly with multiple carrier arms, to allow the transfer of multiple work pieces. The multiple carrier arms are typically not independent, and thus maximum efficiency cannot be realized. Another robot configuration includes multiple independent robot arms which can move independently, and thus can essentially double the throughput with one robot. Still another robot configuration includes two separate robots to transport the wafers for processing.
With advancements in fabrication processes comes the demand for higher throughput, smaller footprint and better functionality. Integrated robot assembly, combining the transfer mechanism with other functions such as object identification and object alignment, can better address this need.